Rechargeable Lithium-ion (Li-ion) batteries are of great interest as power sources for medially implanted or external devices owing to their high theoretical gravimetric and volumetric energy density. We propose to develop a Li-ion battery for Ventricular Assist System (VAS) application based on a novel liquid electrolyte. These electrolytes will be based on new solvents. We intend to demonstrate in Phase I that utilization of short chain asymmetric alkyl carbonates can substantially out perform the benchmark state-of-the-art electrolytes. This system would be environmentally non-intensive by using Li(x)Mn(2)O(4) as a cathode material. Li-ion batteries developed in this project will provide a longer lived power supply for VAS. PROPOSED COMMERCIAL APPLICATION: The Li-ion battery developed in this project will provide high capacity with extended cycle life power source for VAS application. This light-weight compact power source will be economical and environmentally friendly and represents an answer to tomorrow's requirements for batteries used in medically implanted devices, communication devices, small computers and a host of remote equipment.